Electric switch



March 10, 1925'- 1,529,332 E. B. WEDMORE ELECTRIC SWITCH Filed April 14. 1920 Fig. 5. Y Fig.4.

Ira/enter 1 Edmund B. WedmO by W. M

His AtC, (arry- Cil Patented Mar. 10, 1925.

UNITED STATES;

OFFICE.

EDMUND BAsiL' WEnm oitE, greets-ans mm aetam assreiioittrd GENERAL- ELECTRIC COMPANYQA consort-Arron or imw-Yonkw nmozrrtro 'swI'roH;

Applicatlonfiled April- 14; 1920; Sen'alNo. 373,910;

arcing contacts at whichthe circuit is broken; after the main contacts haye beenseparated;

The object of my invention is to PIOVldB a 7 switch of the oil break type-in which, as the contacts separate, oil is permitted to flow toward the arcing contactfroin all sides, and is directed into the arc path-to assist in extinguishing the arc. I Y

In switches of the oil break type, I have found that it is important that the oil sur rounding the contacts shouldbe allowed to fiow freely towards the arcingcontacts whlle the switch is opening. In switches asat present constructed, although the oilinay flow freely towards the contacts from two orthree sides, it is usually hindered bythe cross-arm carrying the 'movable contaet faces and by the attachment of the arcing contacts.

In accordance with my 1nvent1on,-I emplov a construction of auxiliar -or arcin I 2:

and supportlng means therefor contact which permits theoil to have free access to the contacts from all sides and a construction of main movable contact which, during the opening movement of the switch, causes the oil to flow towards the arcing contact so as to assist in extinguishing the arc.

The novel features which I believe to be characteristic of my invention will be .defi nitely indicated in the claims appended here'- to, while the features of construction andmode of operation will be understood by reference to the following description taken in connection with the accompanyii'ig drawing, in which examples of well known types of cont-acts commonly used prior to my in vention are shown in Figs. 1 and 2, which are side and end elevations respectively of a well known type of moving contact for an oil break switch with its cooperating stationary in- Electric arcing contact andin Figs 3 and 4 which are similar views of anotherwell known type of contact structure; while so1ne;pre-- ferred embodiments of my invention are shown lnthe remain ng figures of the drawingin which Figs. 5, 6 and 7 are side and 7 end elevations and plan respectively of an arcing contact for an oil circuit breaker em bodyin'g; the features -'ofmy invention Fig.

8 is a. side elevation similar to that of Fi'g S showing the main brnsh contact and illustratlng the path ofthe oil during; opening of the switch; and Figs. 9, '10- and llpare see tional side elevation, end elevation and-plan respective1y,'ofmy improved structure of arcing and main-contacts.

Figs. 1 and'2 show-the main movable contact 1 and the movable arcing or auxiliary contact2, which co-operate' with the sta tionary arcing contact 3 Ma circuit breaker. The main stationary contact is omitted for purposes of clearness. This is a well known fornr of contact :stiuctui'efor an oil break switch and-it will be seen, that as then'iovable contacts are nioved downwardly to open the circuit, the contact bar tends to force the oil to flow in a direction away from the arc formed betweenthe stationary and movable arcing contacts: I

In'Figs. 3 and ehianother-well known concontact at by means of a broad flat spring 7 and this agaiin during the openingmove- 'ment of theswitch, hinders ,the oil from flowing towards the are formed at the arcing contact.

In Figs; 5 to 8, inclusive, I- have shown my improved contact structure. Inthese fig ures, the arcing contact 8 is relatively wide, as best shown in Figptiyand is held between supporting bars 9 secured to the switch operating inechanism 'in any convenient manner; These bars 9 are made of thin or flat strips of metal mounted, as shown inFi-g. 7., so as tomove 'edgewise through the oil, thereby offering substantially no resistance to the flow of oil. lVhere this type of con tact is used with a main contact of the brush type, as shown in Fig. 8, the bars 9 extend along each side of the main contact and the curvature of the underside of the main contact is such that it tends to force or direct the oil towards the are formed as the switch opens. i

In Figs. 9 to 11, I have shown my 'improved arcing contact in combination with a cross-bar contact, the shape of which has been modified according to my invention. In

these figures, is shown the arcing contact 8 and the strips 9 supporting it. The cross bar main contact 10 is curved on its underside, as will be seen from Fig. 9, so as to cause the oil to flow towards the arc formed at the arcing contact 8 when the switch is opening. I

In opening switches of this type, the movement of the oil would be relatively unimportant were it not that there is a tendency to develop a large body of gas in the neighborhood of the arcing contact. If the oil is given an initial'motion which tends to cause it to flow away from the arc, as in the case o'f'switches as at present constructed, it will continue to move in the samedirection owing to the extension of the are. If, however, the-oil 'is'caused to flow initially towa'rds tl-ie arc, as is the case with my improved construction, it will distort the body of-vapor carrying the arc and tend to suppress it.

What I claim as new and desire to secure by Letters Patent of the United States, is

1. In an electric switch, the combination with stationary main and auxiliary contacts, of'inovable main and auxiliary contacts c0- operating with said stationary contacts and separable therefrom beneath an insulating liquid, said movable main and auxiliary contacts constructed and arranged to cooperate to direct a flow of said liquid into the are formed as said contacts separate and to permit free access of said liquid from all sides to said auxiliary contacts.

2. In an electric switch, the combination with cooperating fixed and movable main contacts separable beneath an insulating liquid, cooperating fixed and movable auxiliary contacts separable beneath said liquid, and supporting means for said movableauxiliary contacts, said means being open below said auxiliary contacts whereby free access is provided for the flow of insulating liquid into the arc path from all sides as the con tacts separate.

3. Inan electric switch, the combination with cooperating fixed and movable main contacts separable beneath an insulating liquid, cooperating fixed and movable auxiliary contacts separable within said liquid, and supporting means for said movable auxiliary contact comprising metal bars secured to each end of said auxiliary contact and movable edgewise through said liquid.

4. In an electric switch, the combination with cooperating fixed and movable, main contacts separable beneath an insulating liquid, cooperating fixed and movable auxiliary contacts separable within said liquid, and

flat metallic supporting bars secured to each 'end of said movable auxiliary contacts and tending beyond and on each side of said movable main contact arranged for edgewise movement through said fluid, and a cooperating movable auxiliary contact carried between the ends of said conducting bars there being permitted free access of said liquid to the arc path from all sides as the contacts separate.

6. In an electric switch having cooperating fixed and movable main and auxiliary contacts separable under oil, said movable auxiliary contact consisting of relatively wide member mounted for edgewise movement through said oil, and flat metal supporting strips secured to each end of said movable auxiliary contact and movable contacts separate, flat conducting bars exv edgewise through said oil, said movable main contact being mounted intermediate said supporting strips and shaped to cooperate with said movable auxiliary contact to direct a flow of oil into the are formed as said contacts separate. 7

7. In an electric switch, the combination with stationary, main and auxiliary contacts within an insulating fluid, of a cooperating movable main contact shaped to direct a flow of said fluid into the are formed as said contacts separate, flat conducting bars extending beyond and one each side of said movable main contact arranged for edgewise 

